1. Field of the Invention
The present invention relates to an automobile having a vehicle drive motor (traction motor). More particularly, the present invention relates to an electric vehicle including a hybrid vehicle. It is noted that the term “automobile” used herein also includes a fuel cell vehicle.
2. Description of Related Art
A vehicle drive motor for use in electric vehicles is normally driven by a high voltage equal to or more than 100V. An output of a main battery for supplying electric power to the vehicle drive motor also has a high voltage equal to or more than 100V. The electric power of the main battery is transmitted to a controller of the vehicle drive motor. In the controller, a DC electric power is converted into an AC electric power and the AC electric power is then supplied to the motor. The controller is normally mounted in a compartment of the automobile (front compartment/engine compartment). The controller for supplying electric drive power to the motor and controlling the motor may be sometimes called “power control unit.” Unless otherwise stated herein, the vehicle drive motor is referred to simply as “motor,” and the controller for supplying the electric drive power to the motor and controlling the motor is referred to simply as “controller.”
There may be a case where the controller is removed from the compartment when maintenance is performed on an automobile. First of all, a power cable connected to an input terminal for receiving power supply from the main battery or an output terminal for power supply to the motor must be removed to allow the removal of the controller. Hereinafter, normal voltage (electric power) of 100V or more for driving the motor will be referred to as “high voltage (high-voltage electric power)” and the input terminal/output terminal for connection with high-voltage electric power line will be referred to as “high-voltage terminal.” The high-voltage terminal is normally covered with a terminal cover for safety purpose. In the removal of the controller, the supply of high-voltage electric power to the controller should be normally cut off. However, it is preferred that the terminal cover is provided with an interlock for ensuring more positive safety of a worker. The term “interlock” used herein means a switch that cuts off an electric power supply path from the main battery to the controller in response to the removal of the terminal cover. In general, the term “interlock” means a contrivance to ensure the safety of the worker or a device, namely a contrivance to disable the device unless a predetermined condition is established. The interlock stated herein is a contrivance that is triggered by the removal of the terminal cover to cut off a high-voltage electric power supply path from the main battery to the controller. An example of such an interlock is disclosed in Japanese Patent Application No. 2005-143200 (JP-2005-143200 A). JP-2005-143200 A discloses the interlock operatively connected with the release of the terminal cover.